Improvement in dental pluggers



UNITED STATES PATENT OEEIoE.

CARL SOHAERFF, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN DENTAL PLUGGERS.

, Specification forming part of Letters Patent No. 217,412, dated July8, 1879; application filed October 11, 1878.

To all whom it may concern:

Be it known that I, CARL SCHAERFF, of the city and county ofPhiladelphia, and State of Pennsylvania, have invented a new and usefulImprovement in Dental Pluggers, of which the following is aspecification.

The objectof this invention is to furnish an improved dental plugger asan angle attachment to the dental engine, which shall be preferable toothers of the kind by its not transmitting a reverse rotation of the armof the engine, and-thereby not injuring the mechanism of the plugger,and which also, by its more effective and satisfactory working of thebit an d bit-holder, and by its simpler construction, shall improve uponothers of the kind known before.

The invention consists in the combination of two rotating shafts withthe spring-hammer, the rear shaft being provided with a coilspring andratchethead corresponding with the ratchet-foot of the forward shaft,the latter held in place by a set-screw and correspondin g recess, andprovided at its head with fangs to lift the spring-hammer.

It also consists in the combination of the bit-holder, therecoil-spring, and the bit with the spring-hammer, which applies itsblows directly to the head of the bit, all of which is fully describedin the following specification.

In the accompanying drawings similar letters of reference indicate likeparts.

Figure l is a plan view of the device embodying my invention. Fig. 2 isa side view of the same, and Fig. 3 is avertical longitudinal section ofthe same. Fig. 4 is a detail view of the bit and bit-holder, and Fig. 5is a detail view of the two rotating shafts. Fig. 6 is a verticalsection indicated in Fig. 1 by a dotted line, and Fig. 7 is a view ofthe springhammer.

W'ithin the cylindrical-case B (see Fig. 3) is inserted the rotatingshaft A, fitting at its swell in the case, and held in position by itscoil-spring M, acting in the rear of the swell. This shaft is providedwith a ratchet-head corresponding to the ratchet-foot of the forwardshaft, N, for the purpose of transmitting theproper rotation to thesame, or neutralizin g the effect of a reverse rotation. The ratchetsare cut on the vertical surface of each shaft (see Fig. 5) obliquely,and reverse to each other, so that the projection of the one fits in therecess of the other, and by being cut obliquely, and also by the aid ofthe coil-spring M, the shaft A will, in case of a reverse rotation,rotate without any effect on shaft N. Thus connected with shaft A bysaid ratchet's shaft N is further provided with a bolt (see Fig.5)projecting from the center of its ratchet-foot, and fitting in thecorresponding hole made in the ratchet-head of shaft A, and also with acircular recess at its swell, in which the smooth end of set-screw O,which fastens the spring-hammer l) to the case B, fits, all for thepurpose of holding said shaft N in place. The head of shaft N, whichrests in socket E, is provided with two fangs. (See Fig. 5.) The curvedsides of these fangs meet the downward-projecting andcorrespondingly-curved fang of the spring-hammer D, (see Figs. 3 and 7,)and thereby, when in rotation, lift the spring-hammer D, which moves ina slot made through the upper surface of case B, and applies its blowsdirectly to the head of the bit. Into the bore of the angled and movablecase of the bit-holder the bit-holder 0 (see Figs. 3 and 4.) is screwed.Through the six-cornered recess in the holder the six-cornered shankedbit P is previously inserted. The socket and bit being six-corneredprevents the turning of the bit in its sockets. Between the bit-holderand the head of the bit is the recoil-spring Q, (see Fig. 4,) which,after each blow from the spring-hammer D, pushes the bit back, and alsokeeps it from falling out.

The operation of the device is as follows: The shaft A, after theconnection with the rotating arm of the dental engine is made,

transmits the proper rotation to shaft N, which lifts the springhammer Dby its fangs, which slide down the curved side of the fang of thespring-hammer. As soon as the one fang of shaft N, by its rotation,leaves the fan g of the spring hammer the latter fang beats down uponthe head of the shaft N, to be lifted up again by the other fang, and soforth, whereby the hammer part of the spring, by each beatingdownmotion, applies a blow on the head of the bit.

I claim-- to receive the bit, and the recoil-spring Q, 1. In a dentalplugger. the combination of and the six-cornered bit P with thespringshaft A, its ratchet-head, and coil-spring M, hammer D,substantially as described.

the shaft N its fangs at the head its ratchetfoot and recess, andset-screw 0 with the v CARL SOHAERFF'. springhmnmer D, substantially asdescribed. Witnesses:

2. In a dental pluggel, the combination of I \VM. L. GOLDY,

the bit-holder 0, having a six-cornered hole I GEO. F. MEEsER, M. D.

